CN112514165B

CN112514165B - Antenna device

Info

Publication number: CN112514165B
Application number: CN201980050410.8A
Authority: CN
Inventors: 山保威; 曾根孝之
Original assignee: Yokowo Co Ltd
Current assignee: Yokowo Co Ltd
Priority date: 2018-07-31
Filing date: 2019-07-30
Publication date: 2024-05-10
Anticipated expiration: 2039-07-30

Abstract

Provided is a small and lightweight antenna device that can be used in a wide frequency range. The 1 st vibrator and the 2 nd vibrator are opposed to each other at a predetermined interval while being rotated by substantially 90 degrees, and the entire vibrator is fixed to the mounting surface while being inclined by a predetermined angle (for example, substantially 45 degrees). Each vibrator has two arm portions (101A and 102A, 201A and 202B) extending in a direction away from each other from a portion connecting the feeding points.

Description

Antenna device

Technical Field

The present invention relates to a thin antenna device that can be used in a wide frequency range from 698MHz and its front-rear frequency to 6GHz and its front-rear frequency, for example.

Background

In recent years, there has been a growing demand for carrying out MIMO (Multiple-Input Multiple-Output) based communications by using a frequency band of LTE (Long Term Evolution: long term evolution) or 5G (5 th generation mobile communication system) while mounting electronic devices on a vehicle. MIMO is a communication scheme in which a plurality of antennas are used to transmit different data from each antenna and simultaneously receive data from the plurality of antennas. As an antenna device capable of realizing such a communication scheme, a MIMO antenna device disclosed in patent document 1 is known.

The MIMO antenna device disclosed in patent document 1 is configured by housing a plurality of unbalanced antennas and balanced antennas, which are antennas, in a shark fin antenna housing having a length of 100mm, a width of 50mm, and a height of 45 mm. The unbalanced antenna is formed by etching a rectangular plane formed of polychlorinated biphenyl. The balanced antenna is composed of two planar L-shaped arms that are symmetrical with respect to each other.

Prior art literature

Patent literature

Patent document 1: japanese patent application laid-open No. 2016-504799

Disclosure of Invention

When the unbalanced antenna is set to a low level as in the MIMO antenna device disclosed in patent document 1, the VSWR (Voltage STANDING WAVE Ratio) is deteriorated and the gain in the horizontal direction is insufficient due to the reduction in the antenna size (height). In addition, when a plurality of antennas are housed in a narrow area such as a shark fin antenna housing, interference between the antennas occurs, which has an unsatisfactory effect on antenna characteristics. For example, in a MIMO antenna device used in LTE, the greater the inter-antenna isolation, the better, but in the MIMO antenna device disclosed in patent document 1, it is difficult to satisfy this condition in a wide frequency band. As shown in fig. 5 to 7 of patent document 1, the usable frequency band is limited to a plurality of locations in the range of 0.6 to 3GHz, and each band is narrow.

The present invention aims to provide an antenna device, which can realize stable operation in a wide frequency band range and reduce the influence of other antennas or vibrators close to the antenna device.

An antenna device according to an embodiment of the present invention includes: a pair of 1 st transducers arranged on the 1 st plane; and a pair of 2 nd oscillators disposed on a2 nd plane parallel to the 1 st plane, the direction of polarization being orthogonal to the pair of 1 st oscillators, each of the pair of 1 st oscillators and the pair of 2 nd oscillators including a portion that operates as a self-similar antenna or an antenna based on the self-similar antenna or the antenna.

More specifically, each of the pair of 1 st oscillators and the pair of 2 nd oscillators has two arm portions extending in a direction away from each other from a base end portion to which a feeding point can be connected, and the two arm portions operate as a self-similar antenna or an antenna based on the self-similar antenna or the arm portions. The "self-similar type antenna" is, for example, a biconical antenna, a bowtie antenna, or the like, which is similar even if the shape of the ratio (size ratio) is changed.

Effects of the invention

The antenna device of the present invention includes a pair of 1 st elements each including a portion that operates as a self-similar type antenna or an antenna based on the self-similar type antenna, and a pair of 2 nd elements having a polarization direction orthogonal to the 1 st elements, and thereby operates as, for example, a notch antenna (one of traveling wave type antennas) in a relatively high frequency band region, that is, a high frequency region, and operates as, for example, a loop antenna (one of resonance type antennas) in a relatively low frequency band region, that is, a low frequency region. The dipole antenna (one of the resonant antennas) operates in a specific frequency band region in the intermediate frequency band region, which is the frequency band region between the relatively high frequency band and the relatively low frequency band. In addition, in the respective bands between the relatively high frequency band, the relatively low frequency band, and the intermediate frequency band, the operation principle of these antennas is compounded, that is, the antennas are operated as compound antennas. Therefore, the antenna device is one antenna device, but can stably operate in a larger frequency band than the conventional antenna device.

In addition, since the directions of polarization of the 1 st vibrator and the 2 nd vibrator are orthogonal to each other, even when the 1 st vibrator and the 2 nd vibrator are close to each other, the influence of interference or the like can be reduced. Therefore, the antenna device can be made thin.

Drawings

Fig. 1A is a perspective view of a housing main body accommodating an antenna unit according to embodiment 1.

Fig. 1B is an end view of one side of fig. 1A.

Fig. 2A is a front view of the antenna unit of embodiment 1.

Fig. 2B is a rear view of the antenna section of embodiment 1.

Fig. 2C is a plan view of the antenna unit of embodiment 1.

Fig. 2D is a perspective view of the antenna unit of embodiment 1.

Fig. 3A is an exemplary view of the 2 nd transducer of one and the other.

Fig. 3B is an exemplary view of a pair of 2 nd vibrators.

Fig. 4A is a VSWR characteristic diagram of one vibrator.

Fig. 4B is a radiation efficiency characteristic diagram of one vibrator.

Fig. 4C is a graph of average gain characteristics for the horizontal plane of the antenna of fig. 3A.

Fig. 5A is a VSWR characteristic diagram of two vibrators.

Fig. 5B is a radiation efficiency characteristic diagram of two vibrators.

Fig. 5C is a graph of average gain characteristics for the horizontal plane of the antenna of fig. 3B.

Fig. 6A is a VSWR characteristic diagram of the feeding point K1 in embodiment 1.

Fig. 6B is a VSWR characteristic diagram of the feeding point K2 in embodiment 1.

Fig. 7A is a radiation efficiency characteristic diagram of the feeding point K1 in embodiment 1.

Fig. 7B is a radiation efficiency characteristic diagram of the feeding point K2 in embodiment 1.

Fig. 8A is a graph showing a power transmission characteristic from the feeding point K1 to the feeding point K2 in embodiment 1.

Fig. 8B is a graph showing a power transmission characteristic from the feeding point K2 to the feeding point K1 in embodiment 1.

Fig. 9A is a front view of the antenna unit of embodiment 1.

Fig. 9B is a front view showing a state in which the antenna unit of embodiment 1 is tilted by a predetermined angle.

Fig. 10A is an average gain characteristic diagram of the horizontal plane of the feeding point K1 in the configuration of fig. 9A.

Fig. 10B is an average gain characteristic diagram of the horizontal plane of the feeding point K2 in the configuration of fig. 9A.

Fig. 11A is an average gain characteristic diagram of the horizontal plane of the feeding point K1 in the configuration of fig. 9B.

Fig. 11B is an average gain characteristic diagram of the horizontal plane of the feeding point K2 in the configuration of fig. 9B.

Fig. 12A is a front view of the comparative example antenna section.

Fig. 12B is a rear view of the comparative example antenna section.

Fig. 12C is a plan view of the comparative example antenna section.

Fig. 12D is a perspective view of the comparative example antenna section.

Fig. 13A is a VSWR characteristic diagram of the comparative example antenna portion.

Fig. 13B is an enlarged view of the low frequency region portion of fig. 13A.

Fig. 14A is a radiation efficiency characteristic diagram of the comparative example antenna section.

Fig. 14B is an enlarged view of the low frequency region portion of fig. 14A.

Fig. 15A is a front view of an antenna unit according to embodiment 2.

Fig. 15B is a rear view of the antenna section of embodiment 2.

Fig. 15C is a plan view of the antenna unit of embodiment 2.

Fig. 15D is a perspective view of the antenna unit of embodiment 2.

Fig. 16A is a VSWR characteristic diagram of the feeding point K1 in embodiment 2.

Fig. 16B is a VSWR characteristic diagram of the feeding point K2 in embodiment 2.

Fig. 17A is a radiation efficiency characteristic diagram of the feeding point K1 in embodiment 2.

Fig. 17B is a radiation efficiency characteristic diagram of the feeding point K2 in embodiment 2.

Fig. 18A is a graph showing a power transmission characteristic from the feeding point K1 to the feeding point K2 in embodiment 2.

Fig. 18B is a graph showing the power transmission characteristics from the feeding point K2 to the feeding point K1 in embodiment 2.

Fig. 19A is an average gain characteristic diagram of the horizontal plane of the feeding point K1 in the configuration of fig. 15A.

Fig. 19B is an average gain characteristic diagram of the horizontal plane of the feeding point K2 in the configuration of fig. 15A.

Fig. 20A is a front view of the antenna unit of embodiment 3.

Fig. 20B is a plan view of the long side portion of the antenna unit of embodiment 3.

Fig. 20C is a side view of a short side portion of the antenna portion of embodiment 3.

Fig. 20D is a perspective view of the antenna unit according to embodiment 3.

Fig. 21A is a VSWR characteristic diagram of the feeding point K1 in embodiment 3.

Fig. 21B is a VSWR characteristic diagram of the feeding point K2 in embodiment 3.

Fig. 22A is a radiation efficiency characteristic diagram of the feeding point K1 in embodiment 3.

Fig. 22B is a radiation efficiency characteristic diagram of the feeding point K2 in embodiment 3.

Fig. 23A is a graph showing a power transmission characteristic from the feeding point K1 to the feeding point K2 in embodiment 3.

Fig. 23B is a graph showing a power transmission characteristic from the feeding point K2 to the feeding point K1 in embodiment 3.

Fig. 24A is an average gain characteristic diagram of the horizontal plane of the feeding point K1 in the configuration of fig. 20A.

Fig. 24B is an average gain characteristic diagram of the horizontal plane of the feeding point K2 in the configuration of fig. 20A.

Fig. 25A is a front view of the antenna unit of embodiment 4.

Fig. 25B is a plan view of the antenna unit according to embodiment 4.

Fig. 25C is a perspective view of the antenna unit of embodiment 4.

Fig. 26A is a VSWR characteristic diagram of the feeding point K1 in embodiment 4.

Fig. 26B is a VSWR characteristic diagram of the feeding point K2 in embodiment 4.

Fig. 27A is a radiation efficiency characteristic diagram of the feeding point K1 in embodiment 4.

Fig. 27B is a radiation efficiency characteristic diagram of the feeding point K2 in embodiment 4.

Fig. 28A is a graph showing the power transmission characteristics from the feeding point K1 to the feeding point K2 in embodiment 4.

Fig. 28B is a graph showing the power transmission characteristics from the feeding point K2 to the feeding point K1 in embodiment 4.

Fig. 29A is an average gain characteristic diagram of the horizontal plane of the feeding point K1 in the configuration of fig. 24A.

Fig. 29B is an average gain characteristic diagram of the horizontal plane of the feeding point K2 in the configuration of fig. 24A.

Fig. 30A is a perspective view of the front side of the antenna unit according to embodiment 5.

Fig. 30B is a perspective view of the back surface side of the antenna unit according to embodiment 5.

Fig. 31A is a perspective view of the antenna unit according to embodiment 6.

Fig. 31B is a front view showing a feeding state of the 1 st transducer in embodiment 6.

Fig. 31C is a front view showing a feeding state of the 2 nd transducer in embodiment 6.

Fig. 32A is a VSWR characteristic diagram of the output end of the coaxial cable F114 in embodiment 6.

Fig. 32B is a VSWR characteristic diagram of the output end of the coaxial cable F214 in embodiment 6.

Fig. 32C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114 in embodiment 6.

Fig. 32D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214 in embodiment 6.

Fig. 32E is a graph showing the power transmission characteristics from the output end of the coaxial cable F114 to the output end of the coaxial cable F214 in embodiment 6.

Fig. 32F is a graph showing the power transmission characteristics from the output end of the coaxial cable F214 to the output end of the coaxial cable F114 in embodiment 6.

Fig. 32G is an average gain characteristic diagram of the level of the output end of the coaxial cable F114 in the configuration of fig. 31A.

Fig. 32H is an average gain characteristic diagram of the level of the output end of the coaxial cable F214 in the configuration of fig. 31A.

Fig. 33A is a front view of the 1 st transducer in embodiment 7.

Fig. 33B is a front view of the 2 nd transducer in embodiment 7.

Fig. 33C is a front view showing a feeding state of the 1 st transducer in embodiment 7.

Fig. 33D is a perspective view showing the entire state of the 1 st vibrator and the 2 nd vibrator.

Fig. 33E is a side view of the antenna section of embodiment 7.

Fig. 34A is a VSWR characteristic diagram of the output end of the coaxial cable F114 in embodiment 7.

Fig. 34B is a VSWR characteristic diagram of the output end of the coaxial cable F214 in embodiment 7.

Fig. 34C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114 in embodiment 7.

Fig. 34D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214 in embodiment 7.

Fig. 34E is a graph showing the power transmission characteristics from the output end of the coaxial cable F114 to the output end of the coaxial cable F214 in embodiment 7.

Fig. 34F is a graph showing the power transmission characteristics from the output end of the coaxial cable F214 to the output end of the coaxial cable F114 in embodiment 7.

Fig. 34G is an average gain characteristic diagram of the level of the output end of the coaxial cable F114 in the configuration of fig. 31A.

Fig. 34H is an average gain characteristic diagram of the horizontal plane of the output end of the coaxial cable F214 in embodiment 7.

Fig. 35A is a VSWR characteristic diagram of the output end of the coaxial cable F114 of the modification.

Fig. 35B is a VSWR characteristic diagram of the output end of the coaxial cable F214 of the modification.

Fig. 35C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114 of the modification.

Fig. 35D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214 of the modification.

Fig. 35E is a graph showing a transmission power characteristic from the output end of the coaxial cable F114 to the output end of the coaxial cable F214 according to a modification.

Fig. 35F is a graph showing a transmission power characteristic from the output end of the coaxial cable F214 to the output end of the coaxial cable F114 according to a modification.

Fig. 35G is an average gain characteristic diagram of the level of the output end of the coaxial cable F114 in the configuration of fig. 31A.

Fig. 35H is an average gain characteristic diagram of the horizontal plane of the output end of the coaxial cable F214 of the modification.

Fig. 36A is a perspective view showing an example of the overall structure of the antenna unit according to embodiment 8.

Fig. 36B is a front view showing a feeding state of the 1 st transducer in embodiment 8.

Fig. 36C is a front view showing a feeding state of the 2 nd transducer in embodiment 8.

Fig. 37A is a VSWR characteristic diagram of the output end of the coaxial cable F114 in embodiment 8.

Fig. 37B is a VSWR characteristic diagram of the output end of the coaxial cable F214 in embodiment 8.

Fig. 37C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114 in embodiment 8.

Fig. 37D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214 in embodiment 8.

Fig. 37E is a graph showing the power transmission characteristics from the output end of the coaxial cable F114 to the output end of the coaxial cable F214 in embodiment 8.

Fig. 37F is a graph showing the power transmission characteristics from the output end of the coaxial cable F214 to the output end of the coaxial cable F114 in embodiment 8.

Fig. 37G is an average gain characteristic diagram of the level of the output end of the coaxial cable F114 in the configuration of fig. 36A.

Fig. 37H is an average gain characteristic diagram of the level of the output end of the coaxial cable F214 in the configuration of fig. 36A.

Fig. 38 is an external view of the antenna device in embodiment 9.

Fig. 39 is an exploded view of the antenna device in embodiment 9.

Fig. 40A is a perspective view of the inside of the 1 st housing as seen from the back side.

Fig. 40B is a front view of the inside of the 1 st housing.

Fig. 40C is a perspective view of the inside of the 2 nd housing as seen from the back side.

Fig. 40D is a front view of the inside of the 2 nd casing.

Detailed Description

Hereinafter, an embodiment example in which the present invention is applied to an antenna device that can be used in a wide frequency band range from 698MHz and its front-rear frequency to 6GHz and its front-rear frequency will be described with reference to the drawings.

[ Embodiment 1]

The antenna device according to embodiment 1 is used in a thin casing in which an antenna portion can be installed in any position in a room or in any position in a vehicle, for example. The thin housing is configured to include a housing main body made of a radio wave transmissive member such as ABS resin, and a holding portion appropriately formed in accordance with the installation site. The case main body has a frame body having a bottomed quadrangular shape and having an accommodating space for an antenna portion therein, and a lid body for sealing the accommodating space. The cover is provided on one of four side surfaces of the frame or one main surface having the largest width to seal the frame.

Fig. 1A shows an example of the shape of the case main body. Fig. 1B is an end view of one side portion (in this example, the longitudinal side L1) of fig. 1A. The housing main body 10 is an example of a housing having a longitudinal side L1 and a lateral side L2 of about 90mm and a depth L3 of about 13 mm. As shown in fig. 1B, the inner dimension of the housing 10 is about 87mm on the inner side L11 and about 10mm on the inner side depth L31 in the case of the longitudinal side L1. The housing main body is sealed by the cover after accommodating the antenna portion. One of a plurality of holding portions (not shown) is provided at the mounting portion of the housing main body in accordance with, for example, the shape of the partition plate on the plane or the like.

The antenna unit housed in the housing main body 10 will be described. Fig. 2A to 2D are diagrams showing a configuration example of the antenna unit, fig. 2A is a front view, fig. 2B is a rear view of fig. 2A, fig. 2C is a top view, and fig. 2D is a perspective view. For convenience of explanation, orthogonal coordinate systems of x-axis, y-axis, and z-axis are defined. The antenna unit includes a pair of 1 st elements arranged on the 1 st plane 100 and a pair of 2 nd elements arranged on the 2 nd plane 200 parallel to the 1 st plane 100 and having a polarization direction orthogonal to the pair of 1 st elements. The configuration of each of the pair of 1 st transducers and the pair of 2 nd transducers will be described with reference to fig. 3A and 3B.

The predetermined portion of each vibrator (in the illustrated example, the portion where the pair of 1 st vibrators are closest to each other and the portion where the pair of 2 nd vibrators are closest to each other) is a portion to which a feeding point can be connected. This portion is referred to as "base end portion". When it is necessary to particularly distinguish between the base end portions of the 1 st and 2 nd transducers, the former is referred to as "1 st base end portion" and the latter is referred to as "2 nd base end portion". One 1 st vibrator (referred to as "one 1 st vibrator" for convenience of description) of the pair has two arm portions 101a, 102a extending in a direction away from the 1 st base end portion, and distal ends of the arm portions 101a, 102a are open end portions.

The 1 st transducer (referred to as "the 1 st transducer of the other party" for convenience of description) of the pair also has two arm portions 101b and 102b extending in a direction away from the 1 st base end portion, and distal ends of the arm portions 101b and 102b are open end portions. The width of each of the two arm portions (e.g., 101a, 102 a) of the 1 st vibrator increases continuously or stepwise as the distance from the 1 st base end portion increases. That is, the respective widths are larger in the region distant from the 1 st base end portion than in the region close to the 1 st base end portion. Further, the relative intervals of the respective members become larger continuously or stepwise as they are away from the 1 st base end portion. That is, the respective relative intervals are larger in the region distant from the 1 st base end portion than in the region close to the 1 st base end portion. This is to make each arm 101a, 102a self-similar antenna such as a biconical antenna or a bowtie antenna or perform an operation based on the self-similar antenna.

The same applies to the two arm portions (e.g., 101b, 102 b) of the other 1 st transducer. The two arm portions (e.g., 101a, 102 a) of the first transducer 1 also extend in a direction away from the two arm portions (e.g., 101b, 102 b) of the second transducer 1.

The pair of 2 nd vibrators has the same shape and structure as the pair of 1 st vibrators. That is, one 2 nd vibrator (for convenience of explanation, referred to as one 2 nd vibrator) in the pair has two arm portions 201a and 202a extending in a direction away from the 2 nd base end portion, and distal ends of the arm portions 201a and 202a are open end portions. The width of each of the two arm portions (e.g., 201a, 202 a) of one 2 nd transducer increases continuously or stepwise as the distance from the 2 nd base end portion increases. That is, the respective widths are larger in the region distant from the 2 nd base end portion than in the region close to the 2 nd base end portion. Further, the respective relative intervals become continuously or stepwise larger as the 2 nd base end portion is distant. That is, the respective relative intervals are larger in the region distant from the 2 nd base end portion than in the region close to the 2 nd base end portion. This is to make each arm 201a, 202a self-similar antenna such as a biconical antenna or a bowtie antenna or perform an operation based on the self-similar antenna. The same applies to the two arm portions (e.g., 201b, 202 b) of the other 2 nd transducer. The two arm portions (e.g., 201a, 202 a) of the one 2 nd transducer also extend in a direction away from the two arm portions (e.g., 201b, 202 b) of the other 2 nd transducer.

Next, the arrangement of the pair of 1 st transducers and the pair of 2 nd transducers will be described. The intermediate point of the distance between the 1 st base end portion of one 1 st transducer and the 1 st base end portion of the other 1 st transducer is referred to as a1 st center portion. The approximate midpoint of the distance between the 2 nd base end portion of one 2 nd transducer and the base end portion of the other 2 nd transducer is referred to as the 2 nd center portion. The 1 st center portion becomes the feed point K1 of the 1 st vibrator, and the 2 nd center portion becomes the feed point K2 of the 2 nd vibrator. The 1 st central portion and the 2 nd central portion overlap when viewed in a plane (e.g., front or back).

The pair of 2 nd transducers is disposed so as to face the pair of 1 st transducers in a state where the 2 nd central portion is rotated 90 degrees from a position facing the 1 st central portion while maintaining the interval D11. Therefore, a fracture ring (a shape in which a part of the ring is cut away and opposed) is formed between the 1 st vibrator and the 2 nd vibrator opposed to each other. In addition, in the 1 st and 2 nd transducers, the directions of polarization are orthogonal. That is, for example, if the direction of polarization of the 1 st vibrator is vertical (vertical polarization), the direction of polarization of the 2 nd vibrator is horizontal (horizontal polarization), whereas if the direction of polarization of the 1 st vibrator is horizontal (horizontal polarization), the direction of polarization of the 2 nd vibrator is vertical (vertical polarization).

Further, "substantially 90 degrees" means that 90 degrees may not be strictly necessary.

The size (outer edge size) of the connection outer edge of the 1 st transducer is the same as the outer edge size of the 2 nd transducer. Therefore, the outer edges of the pair of 2 nd vibrators have the same size before and after rotation. Each transducer is a conductor plate having a thickness of 0.5mm, for example, and the outer edge dimension is a dimension accommodated in the accommodation space of the case main body 10 in fig. 1. For example, the outer edge dimensions of each transducer are about 87mm by about 10mm. The distance D11 between the 1 st plane 100 and the 2 nd plane 200 is about 9mm, which is the inner depth L31 of the housing main body 10.

Next, the vibrator structures of the pair of 1 st vibrators and the pair of 2 nd vibrators will be described in detail. Fig. 3A and 3B are explanatory views of a structural example of the 2 nd transducer. As shown in fig. 3A, the pair of 2 nd transducers are configured such that the two arm portions 201a and 202a of one 2 nd transducer and the two arm portions 201B and 202B of the other 2 nd transducer are symmetrically joined or integrally formed about the 2 nd base end portion (feeding point K2), as shown in fig. 3B.

The portion from each arm 201a, 202a, 201b, 202b to the tip is an open end. The portion of the tip is referred to as an open end. The open end portions are formed so as to ensure a low frequency region (so as to enable use in a lower frequency region), and the areas of the 1 st vibrator and the 2 nd vibrator are mainly ensured to be equal to or more than a certain level. In this example, the shape of the open end is L-shaped, but the shape of the open end is not limited to L-shaped, and may be trapezoidal, diamond-shaped, elliptical, circular, triangular, or the like.

The width of the two arm portions 201a and 202a of the one 2 nd transducer and the width of the two arm portions 201b and 202b of the other 2 nd transducer increase continuously or stepwise from the 2 nd base end portion to the open end portion, respectively. That is, the width of the two arm portions 201a and 202a of the one 2 nd transducer and the width of the two arm portions 201b and 202b of the other 2 nd transducer are larger in the region distant from the 2 nd base end portion and close to the open end portion than in the region close to the 2 nd base end portion and distant from the open end portion. The relative distance between the two arm portions 201a and 202a of one 2 nd transducer and the relative distance between the two arm portions 201b and 202b of the other 2 nd transducer become continuously or stepwise larger as the distance from the 2 nd base end portion increases. That is, the relative distance between the two arm portions 201a and 202a of one 2 nd transducer and the relative distance between the two arm portions 201b and 202b of the other 2 nd transducer are larger in the region distant from the 2 nd base end portion than in the region close to the 2 nd base end portion. By adopting such a structure, the antenna is a self-similar antenna such as a biconical antenna or a bowtie antenna, or an operation based on the self-similar antenna is performed. Thus, the two arm portions 201a and 202a of the one 2 nd transducer and the two arm portions 201b and 202b of the other 2 nd transducer have a substantially V-shape together with the 2 nd base end portion.

The pair of 1 st transducers has the same transducer structure as in fig. 3A and 3B.

Fig. 4A to 4C show antenna characteristics in the case where one of the 2 nd elements (for example, the two arm portions 201a and 202 a) in fig. 3A is used alone as an antenna. Fig. 4A is a VSWR characteristic diagram, fig. 4B is a radiation efficiency characteristic diagram, and fig. 4C is an average gain characteristic diagram of the horizontal plane (xy plane) of the antenna of fig. 3A. Each horizontal axis represents frequency (MHz). The average gain is an average gain in the horizontal plane (the same applies hereinafter). As shown in fig. 4A and 4B, when only the 2 nd element is used as an antenna, the operation as a resonant antenna is dominant in the vicinity of about 900MHz, and the operation as a non-resonant antenna is dominant in the vicinity of 2500MHz or more. As is clear from fig. 4C, the average gain is about-2 dBi or more at about 900MHz to 4500MHz, which is a practical level equivalent to the MIMO antenna device disclosed in patent document 1.

Fig. 5A to 5C show antenna characteristics in the case where the pair of 2 nd elements shown in fig. 3B are operated as antennas. Fig. 5A is a VSWR characteristic diagram, fig. 5B is a radiation efficiency characteristic diagram, and fig. 5C is an average gain characteristic diagram of the horizontal plane (xy plane) of the antenna of fig. 3B. Each horizontal axis represents frequency (MHz). As is clear from fig. 5A to 5C, when a pair of 2 nd transducers are operated as an antenna, VSWR, radiation efficiency, and average gain (dBi) at a frequency around 1500MHz are significantly improved as compared with the case of using one 2 nd transducer shown in fig. 3A. The same antenna characteristics are also used for the pair of 1 st elements.

Next, antenna characteristics of the antenna unit configured as shown in fig. 2A to 2D will be described. The antenna unit is opposed to the pair of 1 st elements in a state where the 2 nd base ends of the pair of 2 nd elements are rotated by approximately 90 degrees from the position facing the 1 st base ends while maintaining the interval D11. That is, a fracture ring is formed between the 1 st vibrator and the 2 nd vibrator facing each other. Therefore, the band region is widened toward the low frequency region side, and the antenna can operate as an antenna of a larger band. The 1 st transducer and the 2 nd transducer are polarized orthogonally. For example, if the polarization of the 1 st vibrator is vertical, the polarization of the 2 nd vibrator is horizontal, whereas if the polarization of the 1 st vibrator is horizontal, the polarization of the 2 nd vibrator is vertical. Therefore, mutual interference can be suppressed. For example, the isolation is significantly improved compared to the case of no rotation.

Hereinafter, a characteristic example of the antenna unit according to embodiment 1 will be specifically described. Fig. 6A is a VSWR characteristic diagram of the feeding point K1, and fig. 6B is a VSWR characteristic diagram of the feeding point K2. Each horizontal axis is frequency (MHz). According to the antenna unit of embodiment 1, the frequency band region usable as the reception wave or the transmission wave is widened toward the low frequency region.

Fig. 7A is a radiation efficiency characteristic diagram of the feeding point K1, and fig. 7B is a radiation efficiency characteristic diagram of the feeding point K2. Each horizontal axis is frequency (MHz). In the antenna portion of embodiment 1, the radiation efficiency in the vicinity of 698MHz is about 0.85 (about 0.17 in the example of fig. 4B, and about 0.3 in the example of fig. 5B). It is known that the frequency of use can be increased toward a lower frequency region.

Fig. 8A is a graph of the passing power characteristics from the feeding point K1 to the feeding point K2, and fig. 8B is a graph of the passing power characteristics from the feeding point K2 to the feeding point K1. The vertical axis of FIG. 8A is 20Log|S21| (dB), the vertical axis of FIG. 8B is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). S21 is an S parameter indicating a transmission coefficient from the feeding point K1 of the 1 st transducer to the feeding point K2 of the 2 nd transducer, and 20log|s21| is a decibel representation of the passing power characteristic. S12 is an S parameter indicating a transmission coefficient from the feeding point K2 of the 2 nd transducer to the feeding point K1 of the 1 st transducer, and 20log|s12| is a decibel representation of the passing power characteristic.

In the antenna unit according to embodiment 1, the isolation between the feeding point K1 and the feeding point K2 is about-30 dB to about-70 dB or less in a wide band ranging from 698MHz and frequencies around and above to about 6 GHz. That is, although the feeding point K1 is close to the feeding point K2, interference between antennas is extremely small.

The present inventors have verified how the antenna characteristics change by tilting the antenna section in the Z plane at a predetermined angle, in which the antenna section in embodiment 1 is provided in the Z plane that is vertically above the X-Y plane parallel to the ground.

Fig. 9A is a front view of the antenna unit of the present embodiment, which is the same as fig. 2A. Fig. 9B is a view showing a state in which the antenna unit is tilted by a predetermined angle θ, for example, approximately 45 degrees counterclockwise. Fig. 10A is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K1 in the configuration of fig. 9A, and fig. 10B is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K2 in the configuration of fig. 9A. The vertical axis represents the average gain (dBi) and the horizontal axis represents the frequency (MHz). In a pair of 1 st vibrators, for example, the average gain is about 1dBi around 698MHz, for example, about-3 dBi around 6 GHz. The amplitude of gain variation at the frequency therebetween is also smaller than in fig. 4C and 5C. In a pair of 2 nd oscillators, for example, the average gain is about-2 dBi around 698MHz, for example, -2dBi around 6 GHz. The average gain fluctuation width at the frequency is smaller than that of fig. 4C and 5C.

Fig. 11A is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K1 when the antenna section is tilted, that is, in the state of fig. 9B, and fig. 11B is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K2 in the state of fig. 9B. In contrast to fig. 10A and 10B, the 1 st oscillator and the 2 nd oscillator each have a gain higher than before rotation in a frequency band of 5GHz or more. In addition, the difference between the maximum value and the minimum value of the gain is about 6dB before rotation, whereas it is as small as about 4dB in the rotated state. That is, it is known that by tilting the antenna portion by approximately 45 degrees and fixing it, the average gain can be improved and variation in the average gain can be suppressed.

Further, approximately 45 degrees means that it is not necessary to be exactly 45 degrees.

In order to explain the characteristic operation of the antenna unit according to embodiment 1, a comparative antenna unit having a similar structure to that of the antenna unit will be described. Fig. 12A is a front view, fig. 12B is a rear view, fig. 12C is a top view, and fig. 12D is a perspective view of the comparative example antenna section. The comparative example antenna unit includes a pair of 1 st bow-tie antennas and a pair of 2 nd bow-tie antennas having the same frequency, material, and vertical and horizontal dimensions as the antenna unit of embodiment 1. The dimensions are dimensions that can be accommodated in the housing main body 10 shown in fig. 1.

The pair of 1 st bow-tie antennas 501 and 502 are disposed on the 1 st plane 500 with the diameter portions of the semicircular plates facing outward. The pair of 2 nd bow-tie antennas 601 and 602 are disposed on the 2 nd surface 600 with the diameter portions of the semicircular plates facing outward. Each bowtie antenna is opposed to the other while maintaining the interval D11 and rotating the closest portion of the arc (for example, the portion of the arc connecting the feeding points K1 and K2) by approximately 90 degrees from the position facing each other.

Fig. 13A is a VSWR characteristic diagram of the comparative example antenna portion, and fig. 13B is an enlarged diagram of the low frequency region portion of fig. 13A. Fig. 14A is a radiation efficiency characteristic diagram of the comparative example antenna portion, and fig. 14B is an enlarged diagram of a low frequency region portion of fig. 14A. Each horizontal axis is frequency (MHz). The measurement conditions of the respective characteristics are the same as those of the antenna section of embodiment 1. The broken line is a characteristic in the case of only the pair of 1 st bow-tie antennas 501 and 502, and the solid line is a characteristic in the case of opposing the pair of 1 st bow-tie antennas 501 and 502 to the pair of 2 nd bow-tie antennas 601 and 602.

These measurement results show that even a pair of bow-tie antennas (for example, the 1 st bow-tie antennas 501 and 502) can be used as a large-band antenna, and that VSWR and radiation efficiency may be reduced by simply rotating one pair of bow-tie antennas and the other pair of bow-tie antennas by approximately 90 degrees from positions where the closest portions of the arcs face each other while maintaining the interval D11. In particular, in the low frequency region, VSWR is minimum around 1000MHz, and the radiation efficiency is also 0.5 or less around 6.

[ Embodiment 2]

Next, embodiment 2 of the present invention will be described. The antenna unit of embodiment 2 is the same as the antenna unit of embodiment 1 in that it includes a pair of 1 st elements and a pair of 2 nd elements whose polarization directions are orthogonal to each other, and in that each element includes a portion that performs an operation based on a self-similar antenna, but the shape and structure of each element are different from those of the antenna unit of embodiment 1. The antenna unit of embodiment 2 has the same size as that of embodiment 1. That is, the housing main body 10 shown in fig. 1 can house the antenna section of embodiment 2. For convenience of explanation, the same reference numerals are used for the components corresponding to the antenna unit of embodiment 1, and the same reference numerals are used for explanation.

Fig. 15A is a front view, fig. 15B is a rear view, fig. 15C is a top view, and fig. 15D is a perspective view of the antenna unit according to embodiment 2. The antenna unit of embodiment 2 includes a pair of 1 st elements and a pair of 2 nd elements. The pair of 2 nd transducers is opposed to the pair of 1 st transducers in a state rotated by approximately 90 degrees while maintaining a predetermined distance D11 from a position where the 2 nd central portion (the portion or port connecting the feeding point K2) is opposed to the 1 st central portion (the portion or port connecting the feeding point K1). The outer edges of the antenna portions are the same size before and after rotation.

A pair of 1 st transducers will be described. One 1 st transducer has two arm portions 101c and 101d extending in a direction away from each other from the 1 st base end portion. The other 1 st transducer also has two arm portions 102c and 102d extending in a direction away from each other from the 1 st base end portion. The arm 101c of one 1 st vibrator also extends in a direction away from the nearest arm 102c of the other 1 st vibrator. Similarly, the arm 101d extends in a direction away from the arm 102d. The first transducer 1 and the second transducer 1 are symmetrically arranged with respect to the first central portion 1, and have a substantially C-shape when viewed from the front.

The arm portions 101c, 101d, 102c, 102d are conductor plates having the same width, and the tip ends thereof are open ends formed in a predetermined shape, for example, in an L shape. The open end of the arm 101c is opposite to the open end of the arm 101d, and the open end of the arm 102c is opposite to the open end of the arm 102 d. Bending regions 1011c, 1011d, 1021c, 1021d are formed at a part of the respective open end portions. The bending regions 1011c, 1011d, 1021c, 1021d are bent by approximately 90 degrees in the thickness direction of the antenna section, i.e., in the direction of the 2 nd transducer, which will be described later. This is to maintain performance and reduce overall size.

The 2 nd transducer will be described. One 2 nd transducer has two arm portions 201c and 201d extending in a direction away from each other from the 2 nd base end portion. The other 2 nd transducer also has two arm portions 202c and 202d extending in a direction away from each other from the 2 nd base end portion. The arm 201c of one 2 nd transducer also extends in a direction away from the nearest arm 202c of the other 2 nd transducer. Similarly, the arm 201d extends in a direction away from the nearest arm 202d. The first 2 nd transducer and the second 2 nd transducer are symmetrically arranged with respect to the 2 nd central portion, and have a substantially C-shape when viewed from the front.

The arm portions 201c, 201d, 202c, 202d are conductor plates having the same width, and the tip ends thereof are open ends formed in a predetermined shape, for example, in an L shape. The open end of arm 201c is opposite to the open end of arm 201d, and the open end of arm 202c is opposite to the open end of arm 202 d. Further, bending regions 2011c, 2011d, 2021c, 2021d are formed in a part of each open end. The bending regions 2011c, 2011d, 2021c, 2021d are bent by approximately 90 degrees in the thickness direction of the antenna portion, that is, in the direction of the 1 st element. This is to maintain performance and reduce overall size.

In addition, the antenna section of embodiment 2 is also formed with a fracture ring, similarly to the antenna section of embodiment 1, and therefore the usable band region can be widened toward the low frequency region side.

Fig. 16A to 19B show antenna characteristics of the antenna unit according to embodiment 2. Fig. 16A is a VSWR characteristic diagram of the feeding point K1, and fig. 16B is a VSWR characteristic diagram of the feeding point K2.

Fig. 17A is a radiation efficiency characteristic diagram of the feeding point K1, and fig. 17B is a radiation efficiency characteristic diagram of the feeding point K2. Each horizontal axis is frequency (MHz). Fig. 18A is a graph showing a power transmission characteristic from the feed point K1 of the 1 st element to the feed point K2 of the 2 nd element, and fig. 18B is a graph showing a power transmission characteristic from the feed point K2 of the 2 nd element to the feed point K1 of the 1 st element. The vertical axis of FIG. 18A is 20Log|S21| (dB), the vertical axis of FIG. 18B is 20Log|S12| (dB), and the respective horizontal axis is frequency (MHz). Fig. 19A is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K1 in the configuration of fig. 15A, and fig. 19B is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K2 in the configuration of fig. 15A. The horizontal axis is frequency (MHz).

The bending regions 1011c, 1011d, 1021c, 1021d, 2011c, 2011d, 2021c, 2021d may be provided in the antenna section of embodiment 1. It was confirmed that the antenna unit of embodiment 2 was fixed by being inclined at approximately 45 degrees on the Z plane as shown in fig. 15B, and thus the average gain in the horizontal plane (xy plane) was stably increased.

[ Embodiment 3]

Next, embodiment 3 of the present invention will be described. The antenna unit of embodiment 3 is the same as the antenna units of embodiments 1 and 2 in that it includes a pair of 1 st and 2 nd elements whose polarization directions are orthogonal to each other, and in that each element includes a self-similar antenna or a portion that performs an operation based on the self-similar antenna, but the shape and structure of each element are different from those of the antenna unit of embodiment 1.

One of the features of the antenna unit of embodiment 3 is that the shape, structure, and size of the 1 st element and the shape, structure, and size of the 2 nd element are different from each other. The outer edge of the antenna section has a rectangular shape when viewed from the front. Thus, a long side portion and a short side portion are produced. The antenna housing 10 shown in fig. 1A and 1B is also a rectangular parallelepiped with a relatively large long side.

For convenience of explanation, the same reference numerals are given to the components corresponding to the antenna portions of embodiment 1 or embodiment 2, and the same reference numerals are given thereto.

Fig. 20A is a front view of the antenna section of embodiment 3, fig. 20B is a side view of the long side portion, fig. 20C is a side view of the short side portion, and fig. 20D is a perspective view.

The antenna unit of embodiment 3 includes a pair of 1 st elements and a pair of 2 nd elements. The pair of 2 nd transducers is opposed to the pair of 1 st transducers in a state rotated by approximately 90 degrees with a predetermined interval maintained from a position where the 2 nd central portion (portion connecting the feeding point K2) is opposed to the 1 st central portion (portion connecting the feeding point K1). The predetermined interval is the same as the interval D11 described in embodiment 1.

A pair of 1 st transducers will be described. One 1 st vibrator has two arm portions 101c and 101d extending in a direction away from each other from the 1 st base end portion, and the other 1 st vibrator has two arm portions 102c and 102d extending in a direction away from each other from the 1 st base end portion. The width continuity or the stepwise increases as the two arm portions 101c and 101d of one 1 st vibrator and the two arm portions 102c and 102d of the other 1 st vibrator are separated from the 1 st base end portion. That is, the width of the two arm portions 101c and 101d of the 1 st vibrator and the width of the two arm portions 102c and 102d of the 1 st vibrator are larger in the region distant from the 1 st base end portion than in the region close to the 1 st base end portion. The relative distance between the 1 st transducer and the 1 st transducer increases continuously or stepwise as the distance from the 1 st base end portion increases. That is, the relative distance between the 1 st transducer and the 1 st transducer is greater in the region distant from the 1 st base end than in the region close to the 1 st base end. The arm 101c of one 1 st vibrator also extends in a direction away from the nearest arm 102c of the other 1 st vibrator. By adopting such a configuration, a self-similar antenna such as a biconical antenna or a bowtie antenna is formed or an operation based on the self-similar antenna is performed.

The distal end portions of the arm portions 101c, 102c, 101d, 102d are open-ended. Each of the open ends is formed in a predetermined shape, for example, an L-shape. The open end of the arm 101c is opposite to the open end of the arm 101d, and the open end of the arm 102c is opposite to the open end of the arm 102 d. Thus, the two arm portions 101C and 101d of the 1 st vibrator and the two arm portions 102C and 102d of the 1 st vibrator are symmetrically arranged with respect to the 1 st center portion, and each have a substantially C-shape when viewed from the front.

Next, a pair of 2 nd transducers will be described. The relative distance between the two arm portions 201c and 202c of the one 2 nd transducer and the two arm portions 201d and 202d of the other 2 nd transducer increases continuously or stepwise as the distance from the 2 nd base end portion increases. That is, the relative distance between the two arm portions 201c and 202c of the one 2 nd transducer and the two arm portions 201d and 202d of the other 2 nd transducer is greater in the region distant from the 2 nd base end portion than in the region close to the 2 nd base end portion. The arm 201c of one 2 nd transducer also extends in a direction away from the nearest arm 201d of the other 2 nd transducer. As described above, the relative distances between the arm portions 201c and 202c and the arm portions 201d and 202d are larger near the open end portion when comparing the vicinity of the base end portion with the vicinity of the open end portion. By adopting such a structure, the antenna is a self-similar antenna such as a biconical antenna or a bowtie antenna, or an operation based on the self-similar antenna is performed.

Thus, the two arm portions 201C and 202C of the one 2 nd transducer and the two arm portions 201d and 202d of the other 2 nd transducer are symmetrically arranged with respect to the 2 nd central portion, and each have a substantially C-shape when viewed from the front.

The distal ends of the arm portions 201c, 201d, 202c, 202d are open ends, respectively. The rate of change of the width of each arm 201c, 201d, 202c, 202d from the vicinity of the 2 nd base end to the vicinity of the open end is smaller than the rate of change of the width of the 1 st vibrator from the vicinity of the 1 st base end to the vicinity of the open end. A long-side bending region 2011c and a short-side bending region 2012c are formed at a part of the open end of the arm 201 c. The long-side bending region 2011c is bent by 90 degrees in the thickness direction of the antenna portion, i.e., in the direction of the nearest 1 st element. The short side bending region 2012c is bent by 90 degrees from the long side bending region 2011c in the direction of the other 1 st transducer.

The open ends of the other arm portions 202c, 201d, 202d are also formed with bending regions having the same structure as the open ends of the arm portion 201 c. That is, a long-side bending region 2021c and a short-side bending region 2022c are formed in a part of the arm portion 202 c. A long-side bending region 2011d and a short-side bending region 2012d are formed in a part of the arm portion 201 d. A long-side bending region 2021d and a short-side bending region 2022d are formed in a part of the arm portion 202 d.

By forming these bending regions 2011c, 2012c, 2021c, 2022c, 2011d, 2012d, 2021d, 2022d, the overall size can be reduced while maintaining the antenna performance in the case where no bending region is formed. Further, since the pair of 1 st and 2 nd transducers are formed with the fracture ring, the usable frequency band region can be widened toward the low frequency region side.

Fig. 21A to 24B show antenna characteristics of the antenna unit according to embodiment 3. Fig. 21A is a VSWR characteristic diagram of the feeding point K1, and fig. 21B is a VSWR characteristic diagram of the feeding point K2.

Fig. 22A is a radiation efficiency characteristic diagram of the feeding point K1, and fig. 22B is a radiation efficiency characteristic diagram of the feeding point K2. Each horizontal axis is frequency (MHz). Fig. 23A is a graph showing a power transmission characteristic from the feeding point K1 of the 1 st element to the feeding point K2 of the 2 nd element, and fig. 23B is a graph showing a power transmission characteristic from the feeding point K2 of the 2 nd element to the feeding point K1 of the 1 st element. The vertical axis of FIG. 23A is 20Log|S21| (dB), the vertical axis of FIG. 23B is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 24A is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K1 in the configuration of fig. 20A, and fig. 24B is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K2 in the configuration of fig. 20A. The horizontal axis is frequency (MHz).

[ Embodiment 4]

Next, embodiment 4 of the present invention will be described. The antenna unit of embodiment 4 is the same as the antenna unit of embodiment 1 in that it includes a pair of 1 st and a pair of 2 nd elements whose polarization directions are orthogonal to each other, and in that each element includes a self-similar antenna or a portion that performs an operation based on the self-similar antenna, but the shape and structure of each element are different from those of the antenna unit of embodiment 1. For convenience of explanation, the same reference numerals are given to the components corresponding to the antenna unit of embodiment 1.

Fig. 25A is a front view of the antenna unit of embodiment 4, fig. 25B is a plan view, and fig. 25C is a perspective view. The basic structure of the antenna unit of embodiment 4 is the same as that of embodiment 1. The interval between the pair of 1 st elements and the pair of 2 nd elements and the outer edge dimension are also the same as those of the antenna section of embodiment 1.

The antenna unit of embodiment 4 is different from the antenna unit of embodiment 1 in that the open end of the arm portion of the 1 st element is in conduction with the open end of the arm portion of the nearest 2 nd element, and is formed integrally in the illustrated example so as to include a loop shape that is a self-similar antenna or a portion thereof that operates as a standard antenna. Therefore, in the antenna section of embodiment 4, the fracture ring is not formed.

Fig. 26A to 29B show antenna characteristics of the antenna unit according to embodiment 4. Fig. 26A is a VSWR characteristic diagram of the feeding point K1, and fig. 26B is a VSWR characteristic diagram of the feeding point K2.

Fig. 27A is a radiation efficiency characteristic diagram of the feeding point K1, and fig. 27B is a radiation efficiency characteristic diagram of the feeding point K2. Each horizontal axis is frequency (MHz). Fig. 28A is a graph showing a power transmission characteristic from the feed point K1 of the 1 st element to the feed point K2 of the 2 nd element, and fig. 28B is a graph showing a power transmission characteristic from the feed point K2 of the 2 nd element to the feed point K1 of the 1 st element. The vertical axis of FIG. 28A is 20Log|S21| (dB), the vertical axis of FIG. 28B is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 29A is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K1 in the configuration of fig. 24A, and fig. 29B is an average gain characteristic diagram of the horizontal plane (xy plane) of the feeding point K2 in the configuration of fig. 24A. The horizontal axis is frequency (MHz).

[ Embodiment 5]

Next, embodiment 5 of the present invention will be described. The antenna unit of embodiment 5 is the same as the antenna unit of embodiment 1 in terms of the arrangement relationship between the pair of 1 st elements and the pair of 2 nd elements, and the shape, structure, and size of each element, but the combination of the pair of elements is different from that of embodiment 1. In addition, the manner of feeding to the point is embodied. For convenience of explanation, the same reference numerals are given to the components corresponding to the antenna portion of embodiment 1.

Fig. 30A is a perspective view showing an example of the structure of the antenna unit according to embodiment 5, and fig. 30B is a perspective view seen from the back side of fig. 30A. In embodiment 1, the 1 st element and the 1 st element are each two inverted V-shaped elements symmetrical about the 1 st center, but in the antenna unit of embodiment 5, the 1 st element in the pair is configured by two arm portions 101a and 101b, and the 1 st element in the other is configured by two arm portions 102a and 102b, thereby being configured as two substantially C-shaped elements symmetrical about the 1 st center. The same applies to the pair of 2 nd transducers. That is, one 2 nd transducer is constituted by two arm portions 201a and 201b, and the other 2 nd transducer is constituted by two arm portions 202a and 202b, whereby two substantially C-shaped transducers are formed symmetrically with respect to the 2 nd center portion as a center.

Even in the combination of the resonators, the directions of polarizations of signals receivable or transmittable in the pair of 1 st and 2 nd resonators are orthogonal, and the respective resonators include portions that operate as self-similar antennas or antennas based thereon, so that the same operational effects as those of embodiment 1 can be achieved.

The 1 st feeder F11 around which the ferrite core is wound is connected to the 1 st center portion of the feeding point, and the 2 nd feeder F21 whose angle is different from that of the 1 st feeder F11 by approximately 90 degrees is connected to the 2 nd center portion of the feeding point. This suppresses leakage current in the low frequency region in which resonance operation is performed at 698MHz or the like, and stabilizes and improves radiation characteristics.

In fig. 30A and 30B, L11 and L21 show coaxial cables serving as examples of the feeder lines F11 and F21.

Modification 1

In embodiments 1,2, 4, and 5, the 1 st transducer and the 2 nd transducer are the same in shape, structure, and size, but the present invention is not limited thereto. As long as the antenna has a shape in which the direction of polarization is orthogonal and the area of the overlapping portion can be reduced, one side may have a different size from the other side.

In embodiments 1,2,4, and 5, the pair of 1 st transducers and the pair of 2 nd transducers are described as being substantially V-shaped or substantially C-shaped, but may be substantially D-shaped, substantially U-shaped, substantially semicircular, substantially semi-elliptical, substantially triangular, or substantially quadrilateral. In the embodiments, the description has been given on the assumption that the feeding points are provided at two places, but the feeding points may be provided at only one place. Since the 1 st vibrator and the 2 nd vibrator are electrically connected, the same operation as in the case of providing two places can be achieved.

In embodiment 1, the example was described in which the antenna section was inclined at approximately 45 degrees on the Z-plane, so that the antenna characteristics were improved, but the antenna sections of embodiments 2 to 5 may be similarly inclined. In addition, not only the pair of 1 st elements or the pair of 2 nd elements, but also in the case where one arm or both arms constituting each element are used as antennas, the same inclination is possible.

Effects of the antenna devices of embodiment nos. 1 to 5

Since the antenna portions of embodiments 1 to 5 are arranged such that the directions of polarization of the pair of 1 st elements and the pair of 2 nd elements are orthogonal, mutual interference between the elements is suppressed, and the antenna device can be thinned. Further, since each of the pair of 1 st and 2 nd oscillators includes a portion that operates as a self-similar antenna or an antenna that is standard for the same, reception and transmission can be performed in a wide frequency band range, and stable operation can be realized in a wide frequency band range.

Further, each of the pair of 1 st and 2 nd oscillators has two arm portions extending in a direction away from each other from a base end portion to which a feeding point can be connected, whereby miniaturization of the oscillator can be achieved. As in the comparative example antenna unit shown in fig. 12A to 12D, when the pair of 2 nd bow-tie antennas 601 and 602 are arranged to face the pair of 1 st bow-tie antennas 501 and 502 in a state rotated by substantially 90 degrees from a state facing the pair of 1 st bow-tie antennas 501 and 502, conductors are sandwiched between the peripheries of the elements of the 1 st bow-tie antennas 501 and 502 and the 2 nd bow-tie antennas 601 and 602.

On the other hand, the pair of 2 nd elements in the antenna section 12 according to embodiments 1 to 5 are disposed so as to face the pair of 1 st elements in a state rotated by approximately 90 degrees from a state facing the pair of 1 st elements, and thus the overlapping area between the elements when the two elements approach each other is reduced. That is, the conductor is not sandwiched between the 1 st vibrator and the 2 nd vibrator.

Therefore, since the scatterer does not enter between the two transducers, fluctuation in reactance can be suppressed, and impedance can be stabilized. Thus enabling a large band.

The following antenna device can be realized: the antenna unit can be housed in a radio wave transmissive housing (housing main body 10) having a vertical and horizontal dimension of 90mm and a thickness of 13mm or less, and thus is small and thin, but can house two antennas excellent in isolation while suppressing interference. The antenna device is provided at any place or any place in a room of a vehicle, for example, and can be used for MIMO in a band region using LTE or 5G.

As shown in fig. 6A to 8B and fig. 16A to 19B, the antenna unit according to embodiment 1 and 2 is excellent in stability in the range from the low frequency band region to the high frequency band region of LTE and 5G, and therefore can be used as an antenna unit for domestic and foreign use without any design change.

By setting the widths to be larger as the distance from the feeding point K1 (K2) increases, particularly, VSWR on the high frequency region side becomes smaller, it is possible to improve radiation efficiency and average gain, and suppress variation thereof. Further, by configuring the pair of 1 st vibrators and the pair of 2 nd vibrators, the pair of 2 nd vibrators are further opposed to the pair of 1 st vibrators in a state rotated by approximately 90 degrees from a state opposed to the pair of 1 st vibrators, and the two vibrators are disposed in proximity to each other, and the opposed end portions are electrically connected to each other, whereby a loop is formed, and a large band in the low frequency region direction in the vicinity of 698MHz can be realized. With such a configuration, for example, the low frequency region side of the usable frequency band which is difficult to be realized in the conventional antenna device can be enlarged, and a larger bandwidth of the usable frequency band can be realized.

Since the distal ends of the two arm portions (e.g., 101a, 101 b) are formed into a predetermined shape determined in accordance with the shape of the installation site, the degree of freedom in the shape of the vibrator can be increased, and a required vibrator area can be ensured in each arm portion. The "required oscillator area" is determined by the resonance frequency of the fracture ring that expands the band of the low frequency region.

Since a part of the region of the two arm portions (for example, 101c, 101 d) farthest from the feeding point (for example, K1) is bent in the direction of the other arm portion (for example, 201c, 201 d) facing the feeding point, the band region can be widened toward the low frequency region without changing the longitudinal and lateral dimensions and thickness of the entire antenna portion (and the case main body 10).

The comparative example antenna unit described in embodiment 1 was configured such that a pair of bow-tie antennas rotated approximately 90 degrees from each other were each set as a large-band antenna, and practical antenna characteristics were obtained when the antenna unit was used with a separation of 40mm or more.

In embodiments 1 to 5, although the example in which the minimum frequency of LTE is 698MHz has been described, when the frequency is increased to about 450MHz toward the low frequency region while maintaining the performance of the antenna according to each embodiment, the size (outer edge size) of the antenna portion when viewed from the front or back and the ratio of the wavelength can be increased accordingly without changing the interval D11 of the antenna portion. Further, although the performance of the antenna according to these embodiments is not good, the frequency can be increased to the low frequency region side of about 450MHz by appropriately setting the width of the arm portion and the area of the portion corresponding to the open end portion without changing the size (outer edge size) of the antenna portion.

[ Embodiment 6]

Next, embodiment 6 of the present invention will be described. In embodiment 6, an antenna unit having a simplified structure in which a vibrator manufacturing process is considered will be described in addition to the operational effects of the antenna units of embodiments 1 to 5. The antenna unit having the pair of 1 st elements and the pair of 2 nd elements, the arrangement relationship thereof, and the power feeding system are substantially the same as those of the antenna units of embodiments 1 to 5. For convenience of explanation, the same reference numerals are given to the components corresponding to the antenna portions of the embodiments described so far, and the same reference numerals are given to the components.

Fig. 31A is a perspective view of the antenna unit in embodiment 6, fig. 31B is a front view showing a feeding state of a pair of 1 st elements, and fig. 31C is a front view showing a feeding state of a pair of 2 nd elements. The antenna unit is a box-shaped resin housing (for example, the housing 10 shown in fig. 1A and 1B) having a length of 60mm in the z direction, a length of 80mm in the x direction, and a length of 15mm in the y direction.

Referring to fig. 31A to 31C, a1 st transducer of one of a pair of 1 st transducers includes: a base end region 101e which is a1 st region formed in an arc shape in a direction (x-axis direction) from the my base end portion toward the base end portion of the other 1 st transducer; an extension region 101f as a2 nd region connected to one end of the base end region 101e in a conductive manner; and another extension region 101g conductively connected to the other end of the base end region 101 e.

The other 1 st transducer also has: a base end region 102e formed in an arc shape from the base end of my to the base end of the 1 st transducer; an extension region 102f connected to one end of the base region 102e in a conductive manner; and another extension region 102g conductively connected to the other end of the base region 102 e. The conductive connection can be realized by solder connection or conductive via. Conductive screws or bolt-nuts, conductive adhesives or conductive wires may also be used to make the two areas conductive.

The base end regions 101e and 102e correspond to a part of the arm portion including the portion connecting the power feeding points in the embodiment described so far, that is, the region near the 1 st base end or the 2 nd base end. The extension regions 101f, 101g, 102f, and 102g correspond to the remaining regions of the partial regions in the arm portions of the embodiments described so far.

The base end region 101e is printed in a strip shape on the front and rear surfaces of the single board PB1, and then is connected to each other by conductive vias 1011e in this example. The board PB1 is configured by a substantially rectangular PCB (Printed Circuit Board; hereinafter the same) in this example. The base end region 102e is also printed in a stripe shape on the front and rear surfaces of the board PB1, and then is connected to each other by conductive vias 1021 e. The closest portion of the two base end regions 101e and 102e is the 1 st central portion (portion or port connecting the feeding point K1) described above. A signal line F111 of a coaxial cable F114 as an example of a feeder line is connected to the base end region 102 e. A ground line F112 as a coaxial cable F114 is connected to the base end region 101 e. Thus, the pair of 1 st elements operates as two dipole antennas. The base end regions 101e and 102e, the extension regions 101f and 101g, and the extension regions 102f and 102g operate as two tapered slot antennas.

Further, by attaching the ferrite core F113 to the coaxial cable F114, the current leaking from the outer layer of the coaxial cable F114 can be cut off. In addition, in order to increase the gain in the frequency band on the low frequency region side in the vicinity of 698GHz, the size of the antenna portion is generally increased, but by mounting the ferrite core F113, the size of the antenna portion can be reduced while securing the gain on the low frequency region side.

Here, in the coaxial cable F114, the connection point with the 1 st transducer is set as a feeding point K1, and the end opposite to the feeding point K1 is set as an output end.

In addition, although an impedance matching circuit is usually provided on the printed board, the antenna of the present embodiment does not require an impedance matching circuit, and the signal line F111 and the ground line F112 of the coaxial cable are directly connected to the board regions 101e and 102e formed on the board PB 1. Therefore, the structure of the whole antenna section is simplified.

The extension regions 101f, 101g, 102f, 102g are metal plates which are substantially perpendicular to the board PB1 and have a width in the direction of the 2 nd vibrator, and are each made of sheet metal. The vicinity of the tips of the extension regions 101f, 101g, 102f, 102g are open ends, respectively. The open end portions are constituted by 1 st end portions 1011f, 1011g, 1021f, 1021g having a trapezoidal shape on a plane perpendicular to the board PB1, and 2 nd end portions 1012f, 1012g, 1022f, 1022g having a substantially triangular shape bent on a plane parallel to the board PB 1. The 2 nd end portions 1012f, 1012g, 1022f, 1022g are formed in a substantially triangular shape to maintain the self-similarity and to fix the impedance, thereby improving the antenna performance (VSWR, radiation efficiency, gain).

In order to avoid the joining of the 2 nd end portions 1012f and 1012g and the 2 nd end portions 1022f and 1022g, a part of the triangular tip may be cut off to have a substantially trapezoidal shape. Each end portion becomes wider as it tends to the top of the respective extension region. By forming the 2 nd end portions 1012f, 1012g, 1022f, 1022g in a substantially triangular shape, the antenna portion as a whole can continue to maintain a similar shape, thereby fixing the impedance and improving the antenna characteristics, particularly VSWR. The two extension regions 101f and 101g of the 1 st transducer and the two extension regions 102f and 102g of the 1 st transducer are symmetrically arranged with respect to the 1 st center portion, and each have a substantially C-shape when viewed from the front (y-axis direction).

Next, a pair of 2 nd transducers will be described. The 2 nd vibrator of one of the pair of 2 nd vibrators has: a base end region 201e formed in an arc shape in a direction (z-axis direction) from the my base end portion to the base end portion of the other 2 nd transducer; an extension region 201f connected to one end of the base end region 201e in a conductive manner; and another extension region 201g conductively connected to the other end of the base end region 201 e. The other 2 nd transducer also has: a base end region 202e formed in an arc shape from the my base end portion toward the base end portion of the one 2 nd transducer; an extension region 202f connected to one end of the base end region 202e in a conductive manner; and another extension region 202g conductively connected to the other end of the base end region 202 e.

The base end region 201e is formed on the board PB2 arranged on a plane parallel to the board PB1 so as to be inclined by about 90 degrees with the 1 st center portion as the center. The board PB2 is a substantially rectangular PCB having a long side extending in a direction orthogonal to the board PB 1. The base end region 201e is printed in a band shape on the front and rear surfaces of the board PB2, and then is connected to each other by conductive vias 2011 e. The base end region 202e is also printed in a stripe shape on the front and rear surfaces of the board PB2, and then connected to each other by conductive vias 2021 e.

The closest portion of the two base end regions 201e and 202e is the 2 nd central portion (portion or port connecting the feeding point K2) described above. A signal line F211 of a coaxial cable F214 as an example of a feeder line is connected to the base end region 202 e. A ground line F212 of the coaxial cable F214 is connected to the base end region 201 e. Thus, the pair of 2 nd vibrators operates as two dipole antennas or as two tapered slot antennas. A ferrite core F213 is mounted on the coaxial cable F214. The effect is the same as in the case of the 1 st vibrator. The base end regions 201e and 202e, the extension regions 201f and 201g, and the extension regions 202f and 202g operate as two tapered slot antennas.

Here, in the coaxial cable F214, the connection point with the 2 nd transducer is set as a feeding point K2, and the end opposite to the feeding point K2 is set as an output end.

The extension regions 201f, 201g, 202f, 202g are metal plates perpendicular to the substrate PB2 and having a width in the direction of the 1 st vibrator, and are each made of sheet metal. The extension regions 201f, 201g, 202f, 202g have open ends near their tips, respectively. The open end portions are constituted by 1 st end portions 2011f, 2011g, 2021f, 2021g having a trapezoid shape on a surface perpendicular to the board PB2, and 2nd end portions 2012f, 2012g, 2022f, 2022g having a substantially triangular shape bent on a surface parallel to the board PB 2. The same applies to the 2nd transducer, but a part of the triangular tip may be cut off to have a substantially trapezoidal shape. Each end portion becomes wider as it tends to the top of the respective extension region. The two extension regions 201f and 201g of one 2nd transducer and the two extension regions 202f and 202g of the other 2nd transducer are symmetrically arranged with respect to the 2nd central portion, and each have a substantially C-shape when viewed from the front (y-axis direction).

A fracture ring is formed between the 1 st end 1011f, 1011g, 1021f, 1021g and the 2 nd end 1012f, 1012g, 1022f, 1022g of the 1 st vibrator and the 1 st end 2021f, 2021g, 2011f, 2011g and the 2 nd end 2022f, 2022g, 2012f, 2012g of the nearest 2 nd vibrator. That is, the two regions are non-conductive, but capacitively coupled. Thus, the entire pair of 1 st and 2 nd oscillators operates as a loop antenna. The fracture ring serves to expand the usable band region of the antenna unit toward the low frequency region.

The antenna unit of embodiment 6 is also inclined by approximately 90 degrees with respect to the pair of 1 st elements, as in the antenna unit of the embodiment example described so far. Therefore, the directions of polarization of signals that can be received or transmitted are orthogonal, and part or all of the respective transducers operate as self-similar antennas or antennas that are standard therefor.

In addition, when a self-similar antenna is made of sheet metal or an oscillator is operated using the same as a standard antenna, the width of the periphery of the base end portion of the connection power feeding point is made as narrow as possible. And thus difficult to achieve. However, the antenna portion of embodiment 6 is configured such that the base end regions 101e, 102e, 201e, and 202e, the conductive connection base end region 101e, the extension regions 101f, 101g, the conductive connection base end region 102e, the extension regions 102f, and 102g, the conductive connection base end region 201e, the extension regions 201f, and 201g, and the conductive connection base end region 202e, and the extension regions 202f, 202g are formed by printing on the substrates PB1 and PB2, and thus the antenna portion is easy to manufacture.

Further, since the base end regions 101e, 102e, 201e, and 202e are connected by printing at two places formed on the front and rear surfaces of the boards PB1 and PB2 by the conductive vias 1011e, 1021e, 2011e, and 2021e, respectively, the radiation resistance and inductance increase and the radiation efficiency increase, as compared with the case of a configuration in which only one place is printed. Further, a partial region of at least one of the pair of 1 st transducers and the pair of 2 nd transducers may be formed on the boards PB1 and PB2. The base end regions 101e, 102e, 201e, and 202e may be formed on only one surface of the boards PB1 and PB2. In this case, the conductive vias 1011e, 1021e, 2011e, 2021e are not required.

Next, the antenna characteristics of the antenna according to embodiment 6 will be described.

Fig. 32A is a VSWR characteristic diagram of the output end of the coaxial cable F114, and fig. 32B is a VSWR characteristic diagram of the output end of the coaxial cable F214. Fig. 32C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114, and fig. 32D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214. Each horizontal axis is frequency (MHz). Fig. 32E is a graph showing a transmission power characteristic from the output end of the coaxial cable F114 to the output end of the coaxial cable F214, and fig. 32F is a graph showing a transmission power characteristic from the output end of the coaxial cable F214 to the output end of the coaxial cable F114. The vertical axis of FIG. 32E is 20Log|S21| (dB), the vertical axis of FIG. 32F is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 32G is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F114 in the configuration of fig. 31A, and fig. 32H is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F214. The horizontal axis is frequency (MHz).

As determined from these antenna characteristics, although the antenna is a very small antenna unit having a z-direction length of less than 60mm, an x-direction length of less than 80mm, and a y-direction length of less than 15mm, it is possible to realize use and practical use in a low frequency region such as 698MHz and front-rear frequencies thereof.

The antenna portion is constituted by a base end region formed on the substrate and an extension region made of sheet metal, and the manner of electrically connecting them can be applied to examples other than those shown in fig. 31A to 31C. For example, the above-described method can be applied to other types of antenna sections including one 1 st element and one 2 nd element.

[ Embodiment 7]

In embodiment 7, as an application of embodiment 6, an example of a case where each element of the antenna portion is manufactured by printing on a substrate is described. Fig. 33A is a front view of a pair of 1 st vibrators in embodiment 7, fig. 33B is a front view of a pair of 2 nd vibrators, fig. 33C is a front view showing a feeding state of the pair of 1 st vibrators, fig. 33D is a perspective view for explaining the state of the 1 st vibrator and the 2 nd vibrator as a whole, and fig. 33E is a side view of an antenna section. Here, the substrate is a square PCB having a thickness of 0.8mm and a side length of 87 mm. For convenience of explanation, the same components as those of the antenna components used in the embodiments described so far will be denoted by the same reference numerals.

The antenna unit according to embodiment 7 is configured such that a pair of 1 st elements is printed on one surface (front surface) of a board PB3 having a planar front and back surface, and a pair of 2 nd elements having a polarization direction orthogonal to the pair of 1 st elements is printed on the other surface (back surface) of the board PB 3.

Referring to fig. 33A, the 1 st element of the pair of 1 st elements has two arm portions 101j and 101k extending in a direction away from each other from a base end portion to which a feeding point can be connected. The arm portion 101j has a region 1011j whose width increases as it moves away from the base end portion, and an open end portion 1012j cut out in a straight line from the other corner portion of the board PB3 toward the center portion of the board PB 3. The arm 101k has a region 1011k having a width that increases as it moves away from the base end portion, and an open end portion 1012k cut out in a straight line from one corner portion of the board PB3 toward the center portion of the board PB 3.

The other 1 st transducer has two arm portions 102j and 102k extending in directions away from each other from a base end portion to which a feeding point can be connected. The arm 102j has a region 1021j whose width increases as it moves away from the base end portion, and an open end portion 1022j cut out in a straight line from the other corner portion of the board PB3 toward the center portion of the board PB 3. The arm 102k has a region 1021k having a width that increases as it moves away from the base end portion, and an open end portion 1022k cut away in a straight line from the other corner portion of the board PB3 toward the center portion of the board PB 3. Each element of the pair 1 st element operates as a self-similar antenna or an antenna using the same as a standard antenna.

As shown in fig. 33C, the signal line F111 of the coaxial cable F114 is connected to the base end portion of one 1 st transducer. The ground line F112 of the coaxial cable F114 is connected to the base end of the other 1 st transducer. Thus, the pair of 1 st elements operates as two dipole antennas or as two tapered slot antennas. Further, a ferrite core F113 is mounted on the coaxial cable F114.

Referring to fig. 33B, one 2 nd oscillator of the pair of 2 nd oscillators has two arm portions 201j and 201k extending in a direction away from each other from a base end portion to which a feeding point can be connected. The arm 201j has a region 2011j having a width that increases as it moves away from the base end portion, and an open end 2012j cut away linearly from the other corner portion of the board PB3 toward the center portion of the board PB 3. The arm 201k has a region 2011k having a width that increases as it moves away from the base end portion, and an open end 2012k cut away linearly from one corner of the board PB3 toward the center of the board PB 3.

The other 2 nd transducer has two arm portions 202j and 202k extending in directions away from each other from a base end portion to which a feeding point can be connected. The arm 202j has a region 2021j whose width increases as it moves away from the base end portion, and an open end portion 2022j cut out in a straight line from the other corner portion of the board PB3 toward the central portion of the board PB 3. The arm 202k has a region 2021k having a width that increases as it moves away from the base end portion, and an open end portion 2022k cut out in a straight line from the other corner portion of the board PB3 toward the central portion of the board PB 3. Each element of the pair of 2 nd elements operates as a self-similar antenna or an antenna using the same as a standard antenna.

A signal line F211 of the coaxial cable F214 is connected to the base end portion of one of the 2 nd transducers. The ground line F212 of the coaxial cable F214 is connected to the base end of the other 2 nd transducer. Thus, the pair of 2 nd dipoles operate as two dipole antennas. Further, a ferrite core F213 is mounted on the coaxial cable F214.

As shown in fig. 33D, a fracture ring is formed between the open end (for example, open end 1012 j) of the arm portion of the 1 st vibrator on the front surface of the substrate PCB3 and the open end (for example, open end 2012 j) of the arm portion of the 2 nd vibrator nearest to the back surface side of the substrate PCB 3. Therefore, the 1 st element and the 2 nd element are non-conductive, but capacitively coupled to each other to operate as a loop antenna.

The antenna characteristics of the antenna unit of embodiment 7 will be described. Fig. 34A is a VSWR characteristic diagram of the output end of the coaxial cable F114, and fig. 34B is a VSWR characteristic diagram of the output end of the coaxial cable F214. Fig. 34C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114, and fig. 34D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214. Each horizontal axis is frequency (MHz). Fig. 34E is a graph showing a transmission power characteristic from the output end of the coaxial cable F114 to the output end of the coaxial cable F214, and fig. 34F is a graph showing a transmission power characteristic from the output end of the coaxial cable F214 to the output end of the coaxial cable F114. The vertical axis of FIG. 34E is 20Log|S21| (dB), the vertical axis of FIG. 34F is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 34G is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F114 in the configuration of fig. 33A, and fig. 34H is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F214. The horizontal axis is frequency (MHz).

As is clear from these antenna characteristics, as shown in fig. 33E, although a thin antenna part having a square shape with a side length of 87mm and a thickness of 0.8mm and a printed portion was used in a low frequency region such as a 698MHz front-rear frequency region, it was found that the antenna part was practical.

In embodiment 7, the structure in which the 1 st vibrator is formed on the front surface of one substrate and the 2 nd vibrator is formed on the back surface has been described, but the structure may be implemented using two substrates. That is, a pair of 1 st transducers may be formed by a conductive pattern on the 1 st surface of one substrate, a pair of 2 nd transducers may be formed by a conductive pattern on the 2 nd surface of the other substrate facing the 1 st surface, and the conductive patterns may be electrically connected by conductive through holes or the like.

Modification of embodiment 7

In embodiment 7, an example is described in which the open end (for example, the open end 1012 j) of the arm portion of the 1 st transducer on the front surface of the board PB3 and the open end (for example, the open end 2012 j) of the arm portion of the 2 nd transducer closest to the back surface side of the board PB3 are non-conductive (a fracture ring is formed). Here, as a modification thereof, a structure in which conduction is provided between an open end (for example, an open end 1012 j) of the arm portion of the 1 st vibrator on the front surface of the board PB3 and an open end (for example, an open end 2012 j) of the arm portion of the 2 nd vibrator closest to the back surface side of the board PB3 will be described. Conduction between the open end (e.g., open end 1012 j) of the arm portion of the 1 st vibrator on the front surface of the board PB3 and the open end (e.g., open end 2012 j) of the arm portion of the 2 nd vibrator closest to the back surface side of the board PB3 can be achieved by soldering, conductive vias, or the like, for example.

Fig. 35A to 35H show antenna characteristics of an antenna unit according to a modification of embodiment 7. The measurement conditions were the same as in embodiment 7. Fig. 35A is a VSWR characteristic diagram of the output end of the coaxial cable F114, and fig. 35B is a VSWR characteristic diagram of the output end of the coaxial cable F214. Fig. 35C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114, and fig. 35D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214. Each horizontal axis is frequency (MHz). Fig. 35E is a graph showing a transmission power characteristic from the output end of the coaxial cable F114 to the output end of the coaxial cable F214, and fig. 35F is a graph showing a transmission power characteristic from the output end of the coaxial cable F214 to the output end of the coaxial cable F114. The vertical axis of FIG. 35E is 20Log|S21| (dB), the vertical axis of FIG. 35F is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 35G is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F114 in the configuration of fig. 33A, and fig. 35H is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F214. The horizontal axis is frequency (MHz).

From the VSWR characteristics of these antennas, it is found that the band of the antenna of embodiment 7 is widened by less than about 1GHz band when comparing the case where the open ends of the closest arm portions are made conductive with the case where the antenna portion of embodiment 7 is made nonconductive.

[ Embodiment 8]

In embodiment 8, an antenna unit having a structure in which the open end of the 1 st element on the front surface of the substrate and the open end of the 2 nd element on the back surface of the nearest substrate in the antenna unit of embodiment 6 are conducted will be described. Fig. 36A is a perspective view showing an example of the overall structure of the antenna unit according to embodiment 8, fig. 36B is a front view showing the feeding state of the pair of 1 st elements, and fig. 36C is a front view showing the feeding state of the pair of 2 nd elements.

Unlike the antenna unit of embodiment 6, there is no fracture ring between the open end of the 1 st element on the front surface of the substrate and the open end of the 2 nd element on the back surface of the nearest substrate, that is, there is no fracture ring between the 1 st ends of the nearest open ends, that is, there are no 2 nd ends 1012f, 1012g, 1022f, 1022g, and 2 nd ends 2012f, 2012g, 2022f, 2022g of the 1 st element bent on the surface parallel to the substrate PB1 to have a substantially triangular shape.

The antenna characteristics of the antenna unit of embodiment 8 are shown in fig. 37A to 37H. The measurement conditions were the same as those in embodiment 6. Fig. 37A is a VSWR characteristic diagram of the output end of the coaxial cable F114, and fig. 37B is a VSWR characteristic diagram of the output end of the coaxial cable F214. Fig. 37C is a radiation efficiency characteristic diagram of the output end of the coaxial cable F114, and fig. 37D is a radiation efficiency characteristic diagram of the output end of the coaxial cable F214. Each horizontal axis is frequency (MHz). Fig. 37E is a graph showing a transmission power characteristic from the output end of the coaxial cable F114 to the output end of the coaxial cable F214, and fig. 37F is a graph showing a transmission power characteristic from the output end of the coaxial cable F214 to the output end of the coaxial cable F114. The vertical axis of FIG. 37E is 20Log|S21| (dB), the vertical axis of FIG. 37F is 20Log|S12| (dB), and each horizontal axis is frequency (MHz). Fig. 37G is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F114 in the configuration of fig. 36A, and 37H is an average gain characteristic diagram of the horizontal plane (xy plane) of the output end of the coaxial cable F214. The horizontal axis is frequency (MHz).

From the VSWR characteristics of these antennas, it is found that the band of the antenna of embodiment 8 is widened by less than about 1GHz band when comparing the antenna portion of embodiment 8 in which the open ends of the closest arm portions are made conductive with each other with the antenna portion of embodiment 6 being made nonconductive.

[ Embodiment 9]

In embodiment 9, a structure of assembling an antenna unit to a housing and a feed system will be described in detail. Here, the case 10 shown in fig. 1A and 1B will be described, but the combined case shown in fig. 38 to 40 will be described. The case is made of radio-wave-transmissive plastic, and is composed of a1 st case 10a and a2 nd case 10b having substantially rectangular shapes in which the inner housing spaces are sealed at the open ends thereof, as shown in fig. 38, which are a front view, a rear view, a top view, a bottom view, a right view, and a left view, and an exploded view shown in fig. 39. Fig. 40A is a perspective view of the inner side of the 1 st case 10A in a state where the pair of 1 st transducers are fixed, as viewed from the back surface side, and fig. 40B is a front view of the inner side of the 1 st case 10A. Fig. 40C is a perspective view of the inside of the 2 nd case 10B in a state where a pair of 2 nd transducers are fixed, and fig. 40D is a front view of the inside of the 1 st case 10 a. Four screw receiving bosses 10a1 to 10a4, each of which is screw-threaded with a screw receiving portion, are formed in the 2 nd housing 10 b. The sealing is performed by inserting the screw 10c from the back surface of the 2 nd housing 10b and screwing, and may be performed by using an adhesive. The 1 st housing 10a and the 2 nd housing 10b at the time of sealing had dimensions of 60mm on the long side, 80mm on the short side and 15mm in thickness, except for the exposed coaxial cables F114, F214.

The antenna portions housed in the respective cases 10a and 10b are formed by deforming the shape or the like of a part of the antenna portion of embodiment 6. That is, a pair of through holes are formed at or near both ends of the base end region 101e on the board PB1 in the pair of 1 st transducers. A pair of through holes are also formed at or near both ends of the base end region 102e on the board PB 1. The through holes are opened in the base end portions of the extension regions 101f, 101g, 102f, 102g made of sheet metal, and metal claws PB1a to PB1d are integrally formed so as to be deformable (bendable) in the vicinity of the distal ends thereof. After the claws PB1a to PB1d are penetrated through the through holes, the base end regions 101e and 102e of the board PB1 are bent in the vicinity of the tips thereof. Thereby, the extension regions 101f, 101g, 102f, 102g and the base regions 101e, 102e on the board PB1 are fixed in a conductive connection state. Further, at this point in time, the claws PB1a to PB1d and the base end regions 101e and 102e may be soldered and fixed.

As described above, the impedance matching circuit is not provided on the board PB1, and the signal line and the ground line of the coaxial cable F114 are directly connected to one and the other of the base end regions 101e and 102 e. The coaxial cable F114 is fixed to one side of the short side of the 1 st housing 10a, which is closer to one end, together with the ferrite core F113.

The 1 st end 1011f, 1011g, 1021f, 1021g and the 2 nd end 1012f, 1012g, 1022f, 1022g are formed along the bottom surface and the side surface of the 1 st housing 10a, respectively. The length of the board PB1 and the lengths of the extension regions 101f, 101g, 102f, and 102g are longer than those of the 2 nd transducer corresponding to the respective structures. On the other hand, the length of the portion (post-branching region) of the extension regions 101f, 101g, 102f, 102g branching from the base end regions 101e, 102e and extending in the distant direction is shorter than the structure corresponding to each structure in the 2 nd transducer. As described above, the opposite 2 nd end portions 1012f, 1012g, 1022f, 1022g of the 2 nd end portions 1012f, 1012g and the tip portions of the 2 nd end portions 1022f, 1022g have a substantially trapezoidal shape by adjusting the capacitance and inductance so as to secure a desired frequency band region.

The pair of 2 nd transducers are also accommodated in the 2 nd case 10b in substantially the same structure. That is, a pair of through holes are formed at or near both ends of the base end region 201e on the board PB2 of the pair of 2 nd transducers. A pair of through holes are also formed at or near both ends of the base end region 202e on the board PB 2. Metal claws PB2a to PB2d penetrating through the through-holes are integrally formed at the base end portions of the extension regions 201f, 201g, 202f, and 202g made of sheet metal. After the claws PB2a to PB2d are penetrated through the through holes, the distal end portions of the base board PB2 are bent in the vicinity of the distal ends thereof at the base end regions 201e and 202 e. Thereby, the extension regions 201f, 201g, 202f, 202g and the base end regions 201e, 202e on the board PB2 are fixed in a state of conductive connection. Further, at this point in time, the claws PB2a to PB2d and the base end regions 201e and 202e may be soldered and fixed.

The substrate PB1 is not provided with an impedance matching circuit, and the signal line and the ground line of the coaxial cable F214 are directly connected to one and the other of the base end regions 201e and 202 e. The coaxial cable F214 is fixed to a side closer to the other end of the short side of the 2 nd case 10a together with the ferrite core F213. Thereby, the closest distance to the coaxial cable F114 is prolonged as much as possible.

The 1 st end portions 2011f, 2011g, 2021f, 2021g and the 2 nd end portions 2012f, 2012g, 2022f, 2022g are respectively formed in shapes along the bottom surface and the side surfaces of the 1 st housing 10 b. As described above, the opposite 2 nd end portions 2012f, 2012g of the 2 nd end portions 2012f, 2012g, 2022f, 2022g and a part of the tip end portions of the 2 nd end portions 2022f, 2022g are shaped like a trapezoid by adjusting the capacitance and inductance so as to secure a desired band region. The nearest open end portions (for example, the 2 nd end portion 1012f and the 2 nd end portion 2022 f) of the pair of 1 st transducers and the pair of 2 nd transducers are non-conductive, and function as a fracture ring. That is, the capacitive coupling also operates as a loop antenna.

As described above, the antenna unit according to the present embodiment operates on different operation principles according to the frequency band to be used, or in a state where these different operation principles are combined. For example, in a frequency band in which the 1 st end 1011f, 1011g, 1021f, 1021g and the 2 nd end 1012f, 1012g, 1022f, 1022g of the pair of 1 st vibrators and the 1 st end 2011f, 2011g, 2021f, 2021g and the 2 nd end 2012f, 2012g, 2022f, 2022g of the pair of 2 nd vibrators are capacitively coupled, an operation (operation a) based on a loop antenna is performed on the entire pair of 1 st vibrators and the pair of 2 nd vibrators.

The pair of 1 st elements and the pair of 2 nd elements operate as two dipole antennas, respectively (operation B). In this case, the longer the length of the portion of the two extension regions 101f and 101g and the extension regions 102f and 102g made of sheet metal that branch from the base end regions 101e and 102e and extend in the direction away from each other, the more the antenna characteristics (VSWR or the like) in the intermediate frequency region move toward the low frequency region side. That is, the band in which the antenna characteristics are stable is widened.

The base end regions 101e and 102e, the extension regions 101f and 101g, and the extension regions 102f and 102g operate as two tapered slot antennas (operation C). In this case, the longer the lengths of the two extension regions 101f and 101g and the extension regions 102f and 102g extending while facing the lengths of the boards PB1 and PB2, the closer the high-frequency region is to the antenna characteristics (VSWR or the like) on the lower-frequency region side. That is, the band in which the antenna characteristics are stable is widened. As described above, the antenna device including one antenna unit operates mainly as a loop antenna in a frequency band on the low frequency region side, operates mainly as a dipole antenna in a frequency band on the intermediate frequency region side, and operates mainly as a notch antenna in a frequency band on the high frequency region side. In addition, the antenna operates as a composite antenna in which the operation principles are combined in the intermediate band. That is, the composite antenna mainly operates as a composite antenna in which the principle of operation of the loop antenna and the principle of operation of the dipole antenna are combined in a range from a frequency band on the low frequency region side to a frequency band on the intermediate frequency region side, and the composite antenna mainly operates as a composite antenna in which the principle of operation of the dipole antenna and the principle of operation of the tapered slot antenna are combined in a range from a frequency band on the intermediate frequency region side to a frequency band on the high frequency region side.

The coaxial cable F114 connected to the pair of 1 st vibrators and the coaxial cable F214 connected to the pair of 2 nd vibrators are fixed at the most distant positions in the 1 st housing 10a and the 2 nd housing 10b, and are used in a separate state outside the housing. Therefore, mutual interference caused by unnecessary electric waves due to the current flowing to the outer layers of the coaxial cables F114, F214 can be suppressed.

In addition, in the case where ferrite cores F113, F213 are not provided in the coaxial cables F114, F214, the operation is possible although the radiation efficiency is reduced on the lowest frequency region side in the band. Therefore, in the application where the radiation efficiency in the frequency band on the low frequency region side can be reduced, the ferrite cores F113 and F213 may be used without being attached to the coaxial cables F114 and F214.

In embodiment 9, the 1 st transducer and the 2 nd transducer are provided with ports for power feeding, and the coaxial cables F114 and F214 are connected to the ports for power feeding. In other words, the antenna device including the antenna unit according to embodiment 9 has ports to which the coaxial cables F114 and F214 for power feeding are connected, respectively. However, the antenna device can be operated even if fed by one coaxial cable by providing a branch circuit or the like. In this case, the coaxial cable connected to either one of the two ports may be removed.

Note that, the description has been made of the case where the lengths of the boards PB1 and PB2 and the lengths of the extension regions 101f, 101g, 102f, 102g, 201f, 201g, 202f, and 202g are different in the pair of 1 st transducers and the pair of 2 nd transducers, but the present invention is not limited thereto. For example, in the case where the 1 st housing 10a, 10b is substantially square in shape, their lengths may be the same.

Claims

1. An antenna device is provided with:

a pair of 1 st transducers arranged on the 1 st plane and having a 1 st central portion; and

A pair of 2 nd vibrators disposed on a 2 nd plane parallel to the 1 st plane and having a 2 nd center portion, the 2 nd center portion being rotated by about 90 degrees with respect to the pair of 1 st vibrators from a position coincident with the 1 st center portion, a direction of polarization of the pair of 2 nd vibrators being orthogonal to the pair of 1 st vibrators,

Each of the pair of 1 st and 2 nd oscillators has a feeding point and two arm portions extending in a direction away from each other from a base end portion to which the feeding point can be connected, the two arm portions operate as a self-similar antenna or an antenna based on the self-similar antenna,

The two arms of the pair of 1 st vibrators are conducted or capacitively coupled with the nearest arm of the two arms of the pair of 2 nd vibrators.

2. An antenna device is provided with:

Each vibrator of the pair of 1 st vibrators and the pair of 2 nd vibrators is provided with a feed point,

Each element of the pair of 1 st elements and the pair of 2 nd elements includes a portion that operates as a self-similar antenna or an antenna that is standard for the self-similar antenna,

The 1 st oscillator is conducted or capacitively coupled with the 2 nd oscillator opposite to the 1 st oscillator,

The 1 st element and the 2 nd element facing each other operate as antennas having different operation principles or composite antennas in which the different operation principles are combined, according to frequency bands.

3. An antenna device according to claim 1 or 2, wherein,

The intermediate point of the distance between the base end portion of one 1 st vibrator of the pair of 1 st vibrators and the base end portion of the other 1 st vibrator is a1 st central portion,

The intermediate point of the distance between the base end portion of one 2 nd vibrator of the pair of 2 nd vibrators and the base end portion of the other 2 nd vibrator is a 2 nd central portion,

In the case where the 1 st central portion and the 2 nd central portion overlap when viewed in plan,

The pair of 2 nd transducers is disposed so as to face the pair of 1 st transducers in a state rotated by substantially 90 degrees from a position where the 2 nd central portion faces the 1 st central portion.

4. An antenna device according to claim 3, wherein,

A feeding point is connected to at least one of the 1 st central portion and the 2 nd central portion.

5. An antenna device according to claim 1 or 2, wherein,

The relative interval between the two arm portions becomes larger as the distance from the vicinity of the base end portion becomes larger.

6. An antenna device according to claim 1 or 2, wherein,

The width of each of the two arm portions becomes larger as it is away from the base end portion.

7. An antenna device according to claim 1 or 2, wherein,

Two arm portions of one 1 st vibrator of the pair of 1 st vibrators and two arm portions of the other 1 st vibrator of the pair of 1 st vibrators extend in directions away from each other.

8. An antenna device according to claim 1 or 2, wherein,

The distal ends of the two arm portions are open ends, and thus form a shape of one of a substantially C-shape, a substantially D-shape, a substantially U-shape, a substantially V-shape, a substantially semicircular shape, a substantially semi-elliptical shape, a substantially triangular shape, and a substantially quadrangular shape together with the base end portion.

9. The antenna device according to claim 8, wherein,

A part of the open end is bent in a direction of the other vibrator facing the open end.

10. An antenna device is provided with:

Each of the pair of 1 st and 2 nd oscillators has a feeding point, a base end portion connecting the feeding points, and a pair of arm portions symmetrically arranged on one plane with the base end portion as a center, at least one of the pair of arm portions operates as a self-similar antenna or an antenna based thereon,

The pair of arm portions of the pair of 1 st vibrators are conducted or capacitively coupled with the nearest arm portion of the pair of arm portions of the pair of 2 nd vibrators,

11. The antenna device according to any of claims 1,2, 10, wherein,

The antenna device can transmit or receive signals in a specific frequency band from 698MHz and the front-rear frequency thereof to 6GHz and the front-rear frequency thereof.

12. An antenna device is provided with:

a1 st vibrator and a 2 nd vibrator disposed on one plane; and

Each feeding point capable of feeding each of the 1 st vibrator and the 2 nd vibrator,

The 1 st vibrator and the 2 nd vibrator are respectively provided with two arm parts and a base end part connected with the feed point,

The 1 st element and the 2 nd element include portions facing each other with the feeding point as a center and each operating as a self-similar antenna or an antenna based thereon,

The two arm portions of the 1 st vibrator extend away from each other from the base end portion,

The two arm portions of the 2 nd vibrator extend from the base end portion in a direction away from each other and also extend in a direction away from the two arm portions of the 1 st vibrator which are opposite to each other,

The relative interval between the 1 st vibrator and the 2 nd vibrator becomes larger continuously or stepwise as the distance from the base end portion increases,

The two arms of the pair of 1 st vibrators are conducted or capacitively coupled with the nearest arm of the two arms of the pair of 2 nd vibrators,

13. The antenna device according to claim 12, wherein,

The width of each of the two arm portions of the 1 st transducer and the two arm portions of the 2 nd transducer is larger than the base end portion at a position distant from the base end portion.

14. An antenna device according to claim 12 or 13, wherein,

The top ends of the two arm parts are open ends,

Thereby having a shape of one of a substantially C-shape, a substantially D-shape, a substantially U-shape, a substantially V-shape, a substantially semicircular shape, a substantially semi-elliptical shape, a substantially triangular shape, and a substantially quadrangular shape together with the base end portion.

15. The antenna device according to claim 12, wherein,

And the 1 st oscillator and the 2 nd oscillator are symmetrical with the feed point as a center.

16. The antenna device according to any of claims 1,2, 10, wherein,

A1 st region including a portion connected to a feeding point and being a part of at least one of the pair of 1 st vibrators and the pair of 2 nd vibrators is formed on a substrate,

The 2 nd region other than the 1 st region is formed of a metal plate,

The 1 st area is connected with the 2 nd area in a conducting way.

17. The antenna device according to any of claims 1,2, 10, wherein,

The pair of 1 st vibrators and the pair of 2 nd vibrators are formed on a substrate.

18. The antenna device according to claim 12, wherein,

A1 st region including a portion connected to a feeding point and being a part of at least one of the 1 st vibrator and the 2 nd vibrator is formed on a substrate,

The 2 nd region other than the 1 st region is formed of a metal plate,

The 1 st area is connected with the 2 nd area in a conducting way.

19. The antenna device according to claim 12, wherein,

The 1 st vibrator and the 2 nd vibrator are formed on a substrate.